accesscontroller.java

使用J2EE编写的网上商店系统

/*
 * Created on 1999-5-19
 */
package sevlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.rmi.RemoteException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Iterator;

import javax.ejb.CreateException;
import javax.ejb.RemoveException;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.rmi.PortableRemoteObject;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import cmp.ItemData;


import stateless.StoreAccess;
import stateless.StoreAccessHome;

/**
 * @author 28-9
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Generation - Code and Comments
 */
public class AccessController extends HttpServlet {
	private StoreAccessHome storeAccessHome=null;
	private StoreAccess myStore=null;
	private static String LOGIN_ERROR_SCREEN="/loginEror";
	private static String LOGIN_SCREEN="/login";
	private static String ITEMS_SCREEN="/showItems.jsp";
	
	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		//TODO Method stub generated by Lomboz
		initStoreAccess();
	}
	/**
	 * 
	 */
	private void initStoreAccess() {
		System.out.println("Entering AccessController.initStoreAccess()");
		try {
			storeAccessHome=getHome();
		} catch (NamingException e) {
			e.printStackTrace();
		}
		System.out.println("Leaving AccessController.initStoreAccess()");		
	}
	/**
	 * @return
	 */
	private StoreAccessHome getHome() throws NamingException {
		Object result=getContext().lookup(StoreAccessHome.JNDI_NAME);
		return ((StoreAccessHome)PortableRemoteObject.narrow(result, StoreAccessHome.class));
	}
	
	private InitialContext getContext() throws NamingException{
		Hashtable props = new Hashtable();

		props.put(
			InitialContext.INITIAL_CONTEXT_FACTORY,
			"org.jnp.interfaces.NamingContextFactory");
		props.put(InitialContext.PROVIDER_URL, "jnp://127.0.0.1:1099");

		InitialContext initialContext = new InitialContext(props);
		return initialContext;
	}
	public void destroy() {
		super.destroy();
		//TODO Method stub generated by Lomboz
	}
	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		processRequest(request,response);
	}
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		//TODO Method stub generated by Lomboz
		processRequest(request,response);
	}
	/**
	 * @param request
	 * @param response
	 */
	private void processRequest(HttpServletRequest request, HttpServletResponse response) 
	   throws ServletException, IOException {
		System.out.println("Entering AccessController.processRequest()");
		String buildUrl=null;
		HttpSession session=request.getSession(true);
		String userAction=request.getParameter("useraction");
		
		if(userAction==null) {
			buildUrl=LOGIN_SCREEN;
		}else {
			if(userAction.equals("dovalidation")) {
				System.out.println("In validateLogin");
				String username=request.getParameter("username");
				String passwd=request.getParameter("passwd");
				if((username==null) || !(loginUser(username,passwd,session))) {
					System.out.println("Error:invalid attempt for username");
					buildUrl=LOGIN_ERROR_SCREEN;
				}else {
					buildUrl=ITEMS_SCREEN;
				}
			}
		}
		
		if(buildUrl==ITEMS_SCREEN) {
			String userID=(String)session.getAttribute("userID");
			try {
				myStore=storeAccessHome.create();
				ArrayList itemsList=myStore.getAllItems();
				//displayAllitems(response,itemsList);
				session.setAttribute("itemsList", itemsList);
				System.out.println("BuilderUrl is: "+buildUrl);
				RequestDispatcher rd=getServletContext().getRequestDispatcher(ITEMS_SCREEN);
				rd.forward(request, response);
				myStore.remove();
			} catch (RemoteException e) {
				e.printStackTrace();
			} catch (CreateException e) {
				e.printStackTrace();
			} catch (RemoveException e) {
				e.printStackTrace();
			}
		}else {
			if(buildUrl==LOGIN_SCREEN) {
				displayLoginScreen(response);
			}else if(buildUrl==LOGIN_ERROR_SCREEN) {
				displayLoginErrorScreen(response);
			}
		}
		
		System.out.println("Leaving AccessController.processRequest()");
	}
	/**
	 * @param response
	 */
	private void displayLoginErrorScreen(HttpServletResponse response) throws IOException {
		response.setContentType("text/html");
		PrintWriter out=response.getWriter();
		out.println("<html><title>MyStore Login Error</title>");
		out.println("<h3>Please try again,your login has failed!");
		out.println("<form method=\"get\">");
		displayLoginDataFiels(out);
		out.println("</form><html>");
		
		if(out!=null) out.close();
	}
	/**
	 * @param response
	 */
	private void displayLoginScreen(HttpServletResponse response) throws IOException {
		System.out.println("Entering AccessController.displayLoginScreen()");
		response.setContentType("text/html");
		PrintWriter out=response.getWriter();
		out.println("<html><title>MyStore Login</title>");
		out.println("<body><h2>Welcome to MyStore</h2></body>");
		out.println("<form method=\"get\">");
		displayLoginDataFiels(out);
		out.println("</form></html>");
		
		if(out!=null)
			out.close();
		System.out.println("Leaving AccessController.displayLoginScreen()");
	}
	/**
	 * @param out
	 */
	private void displayLoginDataFiels(PrintWriter out) {
		out.println("<h3>Please enter your username and password:");
		out.println("<table><tr><td>Username:<td><input name=\"username\" type=\"text\">");
		out.println("<tr><td>Password:<td><input name=\"passwd\" type=\"password\">");
		out.println("</table>");
		
		out.println("<input type=\"submit\" value=\"login\" name=\"loginButton\">");
		out.println("<input type=\"reset\" name=\"resetButton\" value=\"reset\">");
		out.println("<input type=\"hidden\" name=\"useraction\" value=\"dovalidation\">");
	}
	/**
	 * @param response
	 * @param itemsList
	 */
	private void displayAllitems(HttpServletResponse response, ArrayList itemsList) throws IOException {
		response.setContentType("text/html");
		PrintWriter out=response.getWriter();
		out.println("<html><title>List of MyStore items</title>");
		out.println("<form method=\"GET\">");
		out.println("<body><h2>MyStore Items Cataloge</h2></body>");
		if(itemsList.isEmpty()) {
			out.println("<p><h3><b>Items are not avaliable</b></h3>");
		}else {
			out.println("<p><table border=\"1\">");
			out.println("<tr><th><b>ItemID</b>");
			out.println("<th><b>Description</b>");
			out.println("<th><b>Quantity</b>");
			out.println("<th><b>Price</b>");
			
			Iterator items=itemsList.iterator();
			ItemData id=null;
			while(items.hasNext()) {
				id=(ItemData)items.next();
				out.println("<tr><td>");
				out.println(id.getItemID());
				
				out.println("</td><td>");
				out.println(id.getDescription());
				out.println("</td><td>");
				out.println(id.getQuantity());
				out.println("</td><td>");
				out.println(id.getPrice());
				
				out.println("</td></tr>");
			}
			
			out.println("<table>");
		}
		
		out.println("</html>");
		
		if(out!=null)
			out.close();
	}
	/**
	 * @param username
	 * @param passwd
	 * @param session
	 * @return
	 */
	private boolean loginUser(String username, String passwd, HttpSession session) {
		String userid=null;
		
		StoreAccess sa;
		try {
			sa = storeAccessHome.create();
			userid=sa.loginUser(username, passwd);
			session.setAttribute("userID", userid);
		} catch (RemoteException e) {
			e.printStackTrace();
		} catch (CreateException e) {
			e.printStackTrace();
		}
		return (userid!=null);
	}
}